GPG error: http://download.virtualbox.org trusty InRelease: The following signatures couldn't be verified because the public key is not available: NO_PUBKEY 54422A4B98AB5139

1)
$ cat /etc/apt/sources.list
# Repos managed by puppet.
deb http://download.virtualbox.org/virtualbox/debian trusty contrib

2)
$ sudo -E apt-get update
Get:1 http://download.virtualbox.org trusty InRelease [7,152 B]
Ign http://download.virtualbox.org trusty InRelease <====IMP
....
Hit http://in.archive.ubuntu.com trusty/multiverse amd64 Packages
Fetched 7,152 B in 4s (1,451 B/s)           
Reading package lists... Done
W: GPG error: http://download.virtualbox.org trusty InRelease: The following signatures couldn't be verified because the public key is not available: NO_PUBKEY 54422A4B98AB5139
$

3)
$ sudo -E apt-key adv --keyserver keyserver.ubuntu.com --recv-keys 54422A4B98AB5139
Executing: gpg --ignore-time-conflict --no-options --no-default-keyring --homedir /tmp/tmp.KEq2FDuXPb --no-auto-check-trustdb --trust-model always --keyring /etc/apt/trusted.gpg --primary-keyring /etc/apt/trusted.gpg --keyring /etc/apt/trusted.gpg.d/puppetlabs-keyring.gpg --keyring /etc/apt/trusted.gpg.d/puppetlabs-nightly-keyring.gpg --keyring /etc/apt/trusted.gpg.d/rustedhalo.gpg --keyserver keyserver.ubuntu.com --recv-keys 54422A4B98AB5139
gpg: requesting key 98AB5139 from hkp server keyserver.ubuntu.com
gpg: key 98AB5139: public key "Oracle Corporation (VirtualBox archive signing key) " imported
gpg: Total number processed: 1
gpg:               imported: 1
$

4)
$ sudo -E apt-get update
Get:1 http://download.virtualbox.org trusty InRelease [7,152 B]
Get:2 http://download.virtualbox.org trusty/contrib amd64 Packages [1,545 B]  <====IMP
....
Hit http://in.archive.ubuntu.com trusty/multiverse amd64 Packages
Fetched 8,697 B in 4s (1,760 B/s)           
Reading package lists... Done
$